Rotosound Piano String Design

[terryc]

jimmyj..from my mechanics side('cos I like all things almost perfect!) I would have to replace those damaged screws and secure the brass bass block..I reckon M6 threaded inserts with s/steel bolts would keep the block from launching itself.
Just to upset everyone I never have liked Rotosound strings, I always went for Elites S/steel 'cos they were extremely bright sounding, mainly because I liked to slap and get that 80's sound.

[JimmyJ]

Excuse my off topic spin...
 
David,
 
Interesting that you would touch on so many points that relate to my basses...  The bridge above is from my 1980 fretless so not the earliest of my 5s but the strangest combination of graphite, these strings and weird bridge ideas...  Also, the position of the saddles on this bass is relative because it's fretless!  My accuracy is scarcely gonna be effected by that fine adjustment!  Ha!
 
Not sure who got me onto the concept of the bridge/tailpiece combo but it may have come from acoustic guitar.  The idea that instead of the endpoint of the vibrating part of the string bearing down on the bridge as it passes over, the bridge is actually the end of the string and maybe that changes how things vibrate...  Anyway, the physics of this stuff is all a mystery to me.  All I know is I got a lucky combination here.
 
Regarding block material ... I think Mica and the gang have done some experimenting and would certainly have a better idea about what material does what but here's a twist:  When I got my first 5-string in '76 there was a slight problem.  Likely because of the big B-string, the particular strings and gauges I had chosen, and the original channel bridge design, I couldn't get the bridge saddles far enough south to make it intonate correctly.  I needed another 1/4 or so of adjustment.  My dad figured he could make me a new block with the bridge mounting holes offset by 1/4 but the only material he had laying around was a chunk of aluminum.  So that's what he used and it worked great.  I can't say what it did to the sound but since it was a success all 3 of my fretted basses have aluminum blocks!  
 
I also believe things like structure and materials apply differently for bass and for guitar because of the different frequencies of the notes we're dealing with.  And of course for what each individual might be trying to achieve.  There are as many variations of ideas as there are players.
 
And, back to where we always go back to - we are talking about such personal minutiae here - if you picked up my bass it would sound like you and vice versa!  
 
That won't stop us from talking though!
 
Jimmy J

[811952]

If I picked it up, it might sound exactly like you (immediately after having a stroke).
 
John

[JimmyJ]

Hey Terry,
I hear you on the fix-up ideas, it certainly could be done nicer.  But I won't be changing anything unless it really does come apart some day.  It's working too good!
Thanks,
Jimmy J

[dfung60]

Jimmy - Very interesting stuff!  
 
I'm curious about one thing that you mentioned in passing (and which I've heard before)- that the intonation setup on the bridge doesn't matter on a fretless...  
 
I would think that does matter!  With the fretless, you can micro adjust the fundamentals and play in just intonation instead of tempered.   But the intonation at the bridge fixes the non-ideal vibration of the string (because of it stiffness).  Wouldn't you need the intonation to be set properly for the harmonics of a fretted note to be in tune the the fundamental?  On a big, stiff string, the fretted position and harmonics might be offset by 1/4 or more.
 
Obviously, this must be working for you, so I'm respectfully curious if I'm misunderstanding this.
 
The problem that you fixed with the offset sustain blocks is what I meant by the range issue on the pioneering 5-string.  I'd certainly expect this issue - nobody could have anticipated a .125 string before it was built.
 
David Fung

[JimmyJ]

... continuing further off-topic in this freeform thread!
Hey David,
 
Well, yes, it matters.  The goal of adjusting the bridge saddles on fretless is the same as it is on the fretted bass; to make the fingered notes sound in tune by fine-tuning the actual length of the string.  I never understand why larger gauge strings need extra linear length for this to work out but that's what normally happens.  My low-B strings are all set about as long as the bridge will allow.  (Your comment on stiffness must be the answer...)  G and D strings are closely tied for shortest on my boomers basses and that must be a reflection the wire used for core and wrap?  Interesting!  The bass above has the added confusion of 1/2 of bare core before the winding starts.  Who knows what how that effects the length issue?
 
My passing comment about fine-tuning on the fretless is just a reflection of my own inaccuracies on the instrument.  I've obviously set up the bridge so that the fingered notes will be roughly where I expect them to be on the fingerboard ... but really I am not THAT accurate.  Just intonation is something that string quartets and sometimes complete orchestras can do on the fly (as long as there is no piano) but as far as I know I never visit that realm.  It's all I can do to get my (tempered) tuner to show green without using too much vibrato.  HA!
 
Back to the PSDs, you can imagine what a pain it was to manufacture several versions of the strings for different basses.  OK, making Fender P and Ric 4001 sets made some sense but I think making the ball end user adjustable was a great answer.  And I still like these old-school threaded brass cylinders with two opposing allen screws to pinch the wire.  Kinda steam-punky.  HA!!
 
Jimmy J

[jacko]

Back on topic, I last bought a set of superwounds in 1993 for my homemade fretless and they were 'New old stock' then having been out of production for a couple of years. Not only did they have the exposed core, they were 'semi-flatwound' - perfect for a fretless player who prefers a roundwound sound. I still have them on my homemade fretless and they still sound great on the odd occasion I get it out.  
I've only ever used DR red devils on my fretless rogue (apart from the alembic strings it came with obviously) and I love the tone. Plus, despite them being roundwound there's still very little fretboard wear.
 
Graeme

[dfung60]

Graeme -  
 
The smooth strings you had were Superwound Linea 505s.  I thought these were the best of all the Superwounds.  These were the first pressurewound strings that I was aware of.  
 
Rotosound still claims to make these if you don't want the exposed core as Solo Bass model 55.  They still have the really good feel, but I didn't think they sounded as good as the old ones (unfair comparison because of the exposed core).  The 55s seem somewhat thin sounding compared to the 505 Superwounds.
 
David Fung

[dfung60]

Jimmy -  
 
Off topic brief physics class...  If the string had perfect physical behavior, the string would be completely elastic from end to end.  In the real world, strings have stiffness and don't exhibit ideal vibration.  When you play a note, the stiffness makes the string behave like it's shorter than it really is (the ends don't freely vibrate).  Each note in the harmonic sequence is affected differently by the stiffness, which makes for poor intonation - harmonics not in tune with the fundamental.  
 
The stiffness is dependent on the construction and materials of the string.  It's generally what you expect - a big fat B string has a lot more stiffness than a .010 guitar string.  The core wire and way the string is wrapped all affect this.
 
The intonation adjustment is compensating for that stiffness problem.  If you pull the bridge piece back, you make the string length longer which lets you shift the fundamental relative to the harmonics to make a better compromise.  The big bass strings will need more compensation than the little ones.  A PSD string will probably require less compensation than a regular wound string even though the core wire is pretty fat.  
 
I wonder how the string makers decide on the mix of core wire diameter, wraps, etc.  There's a lot of factors there, none of which are right.  I remember reading about the genesis of the Swing Bass set with John Entwistle having them wind different strings at the factory until he got something he liked the feel and sound of.  A number of luthiers that have branded strings made by one of the big manufacturers often really have some small differences from the regular production.  At least one shop has a special formula which is the older size of core wire for what's an otherwise common set.
 
David Fung

[JimmyJ]

David,
 
Thanks for the explanation, that's really interesting.  i remember that strings from different manufacturers would require saddle adjustments so that must be due to the different stiffness based on core size, windings, etc.  And really the B-string overtones are so wonky that I don't often play anything above the 5th fret unless it's a passing note...  On my 34 scale bass the 12th fret is almost exactly 17 from the nut but the B-string requires an extra 1/2 of length to make that 12th fret fundamental sound in tune.  
 
Fascinating!
 
Jimmy J

[mario_farufyno]

Talking about special design strings, does anybody here have ever tried those Hellborg signature strings from DR?

[dfung60]

I haven't tried the Hellborgs, but boy do they look interesting!  I hope somebody has and can chime in.  
 
In particular, I'm curious how well they work on an instrument like an Alembic which doesn't have a piezo.  I guess part of the story here is that only the core wire is magnetic.  
 
David Fung